Review of Film Cooling in Gas Turbines with an Emphasis on Additive Manufacturing-Based Design Evolutions

Film-cooling technology is used in high-temperature components of gas turbines to extend their service lives. Hot-gas path components are susceptible to damage or failure in the absence of film cooling. Much of the optimization research efforts have been focused on film hole shapes, heat/mass transfer measurement techniques, and film cooling performance under various mainstream and coolant side operating conditions. Due to recent rapid advancements in the areas of measurement techniques (e.g., pressure-sensitive paints and fast high-resolution imaging) and metal additive manufacturing (AM), film cooling technology has undergone significant changes and shows potential new development. In this review, a historical perspective is discussed covering over five decades of innovation: the geometrical effects from injection angle and hole shapes; flow effects from density ratio, momentum-flux ratio, blowing ratio, advective capacity ratio, and freestream conditions; and more items related to AM. The impact of AM on film hole design strategies, the challenges posed by state-of-the-art AM technology, and pathways for future research are discussed. A comparative analysis of AM assisted film hole fabrication and conventionally manufactured film holes is elaborated

Review of Film Cooling in Gas Turbines with an Emphasis on Additive Manufacturing-Based Design Evolutions

Film-cooling technology is used in high-temperature components of gas turbines to extend their service lives. Hot-gas path components are susceptible to damage or failure in the absence of film cooling. Much of the optimization research efforts have been focused on film hole shapes, heat/mass transfer measurement techniques, and film cooling performance under various mainstream and coolant side operating conditions. Due to recent rapid advancements in the areas of measurement techniques (e.g., pressure-sensitive paints and fast high-resolution imaging) and metal additive manufacturing (AM), film cooling technology has undergone significant changes and shows potential new development. In this review, a historical perspective is discussed covering over five decades of innovation: the geometrical effects from injection angle and hole shapes; flow effects from density ratio, momentum-flux ratio, blowing ratio, advective capacity ratio, and freestream conditions; and more items related to AM. The impact of AM on film hole design strategies, the challenges posed by state-of-the-art AM technology, and pathways for future research are discussed. A comparative analysis of AM assisted film hole fabrication and conventionally manufactured film holes is elaborated

Oral manifestations of tuberculosis

Tuberculosis (TB) is still among the most life-threatening infectious diseases, resulting in high mortality in adults. A significant proportion of patients (15-25%) exist in whom the active TB infection is manifested in an extrapulmonary site. Healthcare workers, including dentists, are at the frontline and can make an important contribution to the control of this infectious epidemic. Oral TB has been considered to account for 0.1-5% of all TB infections. Nowadays, oral manifestations of TB are re-appearing alongside many forgotten extrapulmonary infections as a consequence of the outbreak and emergence of drug-resistant TB and of the emergence of acquired immune-deficiency syndrome

Effect of chlorhexidine, povidone iodine, and ozone on microorganisms in dental aerosols: Randomized double-blind clinical trial

Objective: Dental handpieces, ultrasonic scalers, air polishers, air abrasion units produce the most visible aerosols. The objective of this study was to assess the effect of chlorhexidine (CHX), povidone iodine (PI), and ozone (OZ) on the microorganisms in dental aerosols. Materials and Methods: A total of 60 patients were included in this study, they were randomly assigned into three groups and were subjected to scaling before and after rinsing with 0.2% CHX, 1% PI or irrigation with OZ. Blood agar plates were used to collect the gravitometric settling of aerosols and were sent for aerobic and anaerobic culture. Results: The results demonstrated high percentage reduction of aerobic and anaerobic colony forming units (CFUs) in all three groups. In aerobic CFUs, CHX showed the highest reduction (57%) at mask position whereas at chest position and at 9 ft, PI showed higher CFU reductions (37% and 47%, respectively). In anaerobic CFUs, CHX showed the highest percentage of reduction at chest level (43%) and at 9 ft (44%). Conclusion: CHX, PI and OZ showed similar effects in reducing aerobic and anaerobic CFU′s at the chest mask and at 9 ft. OZ can be used as a preprocedural agent, considering its beneficial effects

Pleomorphic adenoma of palate

A case of 55-year-old female has been presented, who reported to our centre with an unnoticed painless swelling in the posterior part of hard palate, which was interfering in posterior palatal seal formation during denture fabrication. This swelling was diagnosed as pleomorphic adenoma and complete surgical excision was done along with capsule

Spina bifida experience at SKIMS.

It analyzed 315 patients in terms of age, sex, signs and symptoms. A detailed history was taken and local, physical and systematic examinations were carried out .77.33% patients of these cases were of myelomeningocele , whereas 23.22% patients had a simple meningocela. In 130 patients had consecutive myelomeningocele, 106 patients had vertex presentation, 16 patients exhibited external cephalic version whereas 23 patients had breach presentation. 66 patients delivered spontaneous or low forceps, whereas 12 patients had mid cavity or ventous .Various forms of birth injuries were observed. One third of patients had spinal cord function resulting in paralysis loss of sensation ,reflexes two third of patients seem to have interruption of long spinal tracts. In more than 90 patients the spinal cord control of bladder was defective intermitted catherization was conducted in 32 patients, whereas, 22 patients undergo urinary diversion. 20 new born infants with myelomeningocele had ureteric born infants. Spine bifida means a defect in normal closure of the spinal column at any point. 80 patients underwent shunt surgery for the control of hydrocephalous presented in 95 patients. 90 patients had repair of spina bifida lesions survival rate was 84%